2. TOURNIQUET
The term TOURNIQUET was coined by Petit in 1718.
DEFINITION-
Tourniquet is constricting or compressing device used
to control venous and arterial circulation to the upper
and lower extremities for a period of time.
4. Introduction:
In many orthopaedic surgeries on the upper and lower limbs a
bloodless field is important as it helps in the recognition of tissues and
eliminates delay and trauma caused by repeated swabbing.
To provide a bloodless field, blood must be removed from the limb and
then prevented from re-entering it.
Elevation of the limb and reflex vasoconstriction which follows these
decreases the volume of blood within it but more complete
exsanguination can be achieved by actively squeezing the blood out of
the limb.
5. Functions:
Promote optimum surgical conditions(creates a blood
less field )
To control bleeding in life or limb threatening
situations.
To engorge vessels for venipuncture.
6. Parts of Tourniquet:
Inflatable cuff
Gas source (Nitrogen or air)
Pressure display
Pressure regulator
Connection tubing
8. Shape of the cuff of Tourniquet-Curved tourniquets
on conical extremities require significantly lower
arterial occlusion pressures than straight (rectangular)
tourniquets.
The use of straight tourniquets on conical thighs
should be avoided, especially in extremely muscular or
obese individuals.
11. Non-Pneumatic
A type of strap or rubber band that is wrapped around
the extremity to exsanguinate the blood.
The danger with non-pneumatic tourniquet whether
straps or rubber bandage is that the pressure exerted
by them on the underlying tissues is unknown.
12. EXSANGUINATION:
The simplest way to remove most of blood from limb is
to elevate the limb as vertically as possible for four
minutes.
Blood drains from the veins under the effect of gravity,
and this is followed by reflex arteriolar constriction
which makes the emptying more complete.
13. Exsanguination by Esmarch
Bandage:
Esmarch tourniquet is used in some areas and is the
safest and most practical of the elastic tourniquets.
It is applied in area where there is more muscle bulk
for example in mid and upper thigh and Arm.
The Esmarch tourniquet is applied in layers, one on
the top of other; a narrow band produces less tissue
damage than does a wide one.
15. Contraindications to exsanguination:
Severe infections and tumor –In these expressive
exsanguination must not be used to avoid
dissemination.
Proven or suspected Deep vein Thrombosis-In this
fatal massive pulmonary embolism can occur.
16. Pneumatic:
It is an air inflated cuff to constrict blood flow.
A regulating device on the tourniquet machine that can
control amount of cuff pressure.
NON-AUTOMATIC : A non automatic pneumatic
tourniquet consist of a pneumatic cuff, a hand
operated pump and pressure gauge.
The pressure in the cuff is known but there is no
automatic compensation for leaks in the system.
17.
18. Pneumatic:
Automatic : In an automatic pneumatic tourniquet
there is a constant supply of gas to compensate for any
leaks in the system.
19. Site for Application:
Tourniquet must only be placed around the upper arm
or thigh.
These are the only places where there is sufficient
muscle bulk to distribute the pressure in the cuff
evenly, and thus avoid local high pressure areas over
tissues close to surface.
Cuffs must not be placed around forearm,wrist or
ankle.
20. TOURNIQUET PRESSURE:
. For the upper limb: 50 to 100 mm of Hg higher than the
systolic blood pressure (200-250 mm of Hg)
. For the lower limb – Double than the systolic blood
pressure (250-350 mm of Hg)
. The correct pressure depends on the age of patient,
blood pressure, and the size of the extremity.
. Wide tourniquet cuffs are more effective at lower
inflation pressure than are narrow ones.
21. TOURNIQUET TIME:
Tourniquets must be applied for shortest possible
time, compatible with surgery.
The time may vary with the age of patient and the
vascular supply of extremity.
In an average healthy adult younger than 50 years of
age, we prefer to leave the tourniquet inflated for no
more than 2 hours.
For upper limb- preferable time is 1 and half hour
For lower limb – preferable time is 2 hour
23. Contraindication for use of
tourniquet:
1.Peripheral arterial disease.
2. Severe crushing injuries.
3. Sickle cell Disease- Under anoxic condition the RBC
sickle, blood viscosity increases , vessels become block
and a severe episode of thrombosis and haemolysis,
may occur, particularly on release of tourniquet.
4. Patient with past history of deep vein thrombosis and
pulmonary embolism.
5.Patients with established Diabetic Neuropathy-There
is ischemia due to arteritis/atheroscelorosis.
24. Dangers of a Tourniquet
The dangers from the use of tourniquet can result:
1.From the process of exsanguination
2.From pressure on the tissue under the tourniquet
3. From Ischemia
4. From bleeding after the closure of wound and from
failure to remove tourniquet at the end of surgery.
25. Dangers from exsanguination: Exsanguination by
elevation is not hazardous, but there are risk when it is
achieved by compression.
Frictional shearing forces from a tightly applied
Esmarch Bandage can damage the skin, especially
when it is weakened by conditions such as Senility,
Rheumatoid arthritis, steroids or Ehler danlos
syndrome.
The ends of fractured bones,bone screws or foreign
body may damage skin or soft tissue if the bandage is
applied tightly.
Nerves which lie subcutaneously can be damaged
unless protected by additional padding.
26. In the elderly patient a tourniquet should be applied to
only one limb at a time. Effective exsanguination of
both lower limb will result in 15% of circulating blood
volume being forced back into remaining circulation,
this extra cardiac load cannot be tolerated by elderly or
unfit patient.
27. Dangers from the Pressure in the Tourniquet
Cuff:
Most tourniquet cuffs need a layer of foam padding
under them to protect the skin from pinching and
abrasion as the cuff is inflated.
Ocassionaly walls of arteries are stiffened by calcium
deposits which cannot be compressed by normal cuff
pressures. If the pressure is increased there is risk that
vessel wall will fracture and the blood supply to the
limb will be damaged permanently.
28. Even if the pressure in the cuff is normal, local damage
under the cuff can occur if the skin is fragile, the bone
is irregular, or normal padding from muscle or fat is
absent for example in cachexia, severe rheumatoid
arthritis, and poliomyelitis. In these situations, extra
padding under the cuff must be used.
If the pressure in the cuff is higher than necessary,
normal skin, muscles, and nerves are at risk.
29. Muscle is the tissue most likely to suffer permanent
damage,but the most severe functional disability
results from damage to nerves.
When a nerves sustains local injury from pressure the
effect is seen over the whole area distal to the site of
injury, supplied by that nerve. The effect of injury to a
muscle is restricted to that muscle and its action.
30. Dangers from bleeding after the closure
of wound
If a tourniquet is released before the wound is closed,
any major source of hemorrhage can be identified and
can be controlled.
This may prevent the formation of haematoma
jeopardising wound healing.
With some surgery there is bleeding from bone which
cannot be stopped until a firm dressing is applied.In
these cases it is better to insert a drain and keep the
cuff inflated until the dressing is secure.
31. Complications:
Asymptomatic/symptomatic pulmonary embolism.
Chemical burn from solutions seeping underneath the
tourniquet.
Superficial slough/abrasion of skin.
Tourniquet paralysis syndrome.
Post Tourniquet Syndrome.
Compartment Syndrome.
Rhabdomyolysis.
Vascular complications.
32. TOURNIQUET PARALYSIS
SYNDROME :
The tourniquet paralysis syndrome is caused by
pressure rather than ischemia:
It is described by:
1.Motor paralysis with hypotonia or atonia
2.Sensory dissociation
3.The colour and temperature of skin are normal as
sympathetic function is not affected
4.Peripheral pulses are normal.
33. POST TOURNIQUET SYNDROME:
Following the release of a tourniquet there is
immediate swelling of tissue due to reactive
hyperaemia and increased capillary permeability to
fluid and protein.
If this swelling is severe and allowed to persist the
condition merges into Post tourniquet syndrome.
The Post tourniquet syndrome is probably due to
ischemia and its duration.
34. Post tourniquet syndrome consist of the following :-
1.Puffiness of hand and fingers.
2. Stiffness of joints in hand.
3.Colour changes in hand which is pale when elevated
and congested when dependent.
4.Sensation of numbness.
5.Weakness of muscle in hand and forearm without
real paralysis.
35. Prevention of Post tourniquet
syndrome:
To decrease the congestion of tissues and to minimise
hematoma formation at the operative site:
1.Select the correct surgery for each patient.
2.Avoid wasting time by careful pre-operative planning
of surgery.
3.Donot extend the tourniquet time unnecessarily.
4. Elevate the limb after the surgery.
5.Encourage patient to perform active movements of
pertinent limb.
36. Pediatric Tourniquet:
Pediatric patients need pediatric tourniquets because
infants and children have smaller limb circumferences and
limb lengths, different mass of muscle and other soft
tissues, and different physiological characteristics such as
blood pressure and heart rate.
To ensure safe and effective tourniquet use in these
populations, it is important to use personalized tourniquet
cuffs and personalized tourniquet pressures.
37. Personalized pediatric tourniquet
cuffs:
Personalized tourniquet cuffs designed for pediatric
patients are available in a variety of sizes and can have
cylindrical or a variable contour design.
Multiple cuffs widths and lengths are available for
neonatal to adolescent patients.
For adolescent patients with tapered limbs, variable
contour designs are also available.
38. These cuffs are designed to better match patient’s limb
size and shape and thus provide more efficient
application of cuff pressure to the limb, allowing lower
and safer tourniquet pressure.
41. Matching limb protection sleeves are also available to
improve safety by protecting skin underneath the
tourniquet cuffs during tourniquet use.
42. Personalized pediatric tourniquet
pressure:
Personalized tourniquet pressure reduce the risk of
tourniquet related injuries by enabling the use of lower
tourniquet pressure levels and lower tourniquet cuff
pressure gradients to the patient.
This is accomplished by measuring each patient’s Limb
Occlusion Pressure[LOP] and setting a tourniquet
pressure for that patient based on LOP.
43. Limb Occlusion Pressure:
Limb occlusion pressure can be defined as the minimum
pressure required, at a specific time in a specific tourniquet
cuff applied to a specific patient’s limb at a specific
location, to stop the flow of arterial blood into the limb
distal to the cuff.
Many studies published in clinical literature have shown
that higher tourniquet pressures are associated with higher
risk of tourniquet related injuries.
44. When a tourniquet is used in surgery, the best practice is to
use the lowest tourniquet pressure that is safely possible
and to use a tourniquet cuff that is designed to produce the
lowest pressure gradient.
LOP is personalized to each individual patient and each
individual surgical procedure.
Setting the tourniquet pressure on the basis of LOP
minimizes the risk of tourniquet related injuries.
45. Pressure gradient beneath a
tourniquet cuff:
Pressure gradient is defined as variation in pressure
applied by pressurized tourniquet cuff to the
underlying limb across the width of the cuff.
It is affected by tourniquet pressure level and by the
design and the width of pressurized cuff.
46.
47. Setting tourniquet pressure based
on Limb Occlusion Pressure:
The best practice for setting tourniquet pressure is to set a
personalized pressure that is based on Limb occlusion pressure.
The currently established guideline for setting tourniquet
pressure based on LOP is that additional safety margin of
pressure is added to measured LOP, to account for physiologic
variation and other changes that may be anticipated to occur
normally over the duration of surgical procedure.
48. A safety margin of 40-100 mm hg above the LOP has
been suggested.
Typically the safety margin is lower for lower LOP
levels and higher for higher LOP levels.
49. Measurement of LOP:
We can measure LOP manually by palpation or
Doppler ultrasound, or automatically using a distal
photoplethysmographic sensor or a dual purpose
tourniquet cuff.
51. An automatic plethysmographic system built into the tourniquet
instrument that measures LOP in about 30 seconds at the beginning of
operative procedure has been developed and is widely used in surgical
settings.
The automated system incorporates a probe placed on digit of patient’s
operative limb.
The probe detects the presence of arterial pulsations in the limb distal
to the tourniquet cuff as an indicator of arterial blood flow past the cuff
and into the distal limb.
52. By automatically inflating the tourniquet cuff in
predetermined steps having consistently defined
durations, the minimum cuff pressure at which arterial
blood flow past the cuff is stopped can be accurately
determined.
This cuff pressure is patient’s personalized limb
occlusion pressure.
53. Manual measurement of LOP using
a Doppler ultrasound
One technique for manual measurement of LOP based on monitoring arterial
pulsations as an indicator of arterial blood flow is as follows: tourniquet cuff
pressure is increased by an operator slowly from zero while monitoring arterial
pulsations in the limb distal to the cuff until the pulsations can no longer be
detected; the lowest tourniquet cuff pressure at which the pulsations can no longer
be detected can be defined as the ascending LOP. A second manual technique is that
an operator can slowly decrease tourniquet cuff pressure while monitoring to detect
the appearance of arterial pulsations distal to the cuff; the highest pressure at which
arterial pulsations are detected can be defined as the descending LOP.
